Zenith Z-171 gives error when booting from floppy?

[Capt. 2110]

Whenever I try to boot my MS-DOS 3.3 disk, the system shows this error:
BATTERY DEAD - SYSTEM HALTED

Which battery would halt the system, and how can I replace it? Thanks!

P.S. I’m also curious what’s behind the plastic door on the back. I can’t get mine off at the moment.

 

[Capt. 2110]

UPDATE: I removed the back cover with the four screws. Behind the door is the RAM board and an unknown board. I determined the machine is tripping the low battery indicator due to s faulty floppy drive. I took the drive apart to check for any obvious failure, but I found nothing, so I moved the drive motor and read heads to make sure they weren’t stuck and reassembled everything. Now I have a new problem. I tell it to read the disk, and I here a faint buzz for a split second, and then nothing. The drive light doesn’t come on, and I can’t hear the disk spinning. But the computer no longer thinks the battery is dead, so I’m a bit further ahead. Any recommendation as to what to try next?

Edit: I also found a ram chip (HM50256) with pin 5 bent in. I bent it back to normal. No change as far as I can tell.

 

[Capt. 2110]

UPDATE: did a little more testing. If I tell it to boot but leave the floppy cable unplugged it still tried to run the drive. So I’m sure it’s not a drive controller issue.

 

[Capt. 2110]

Switched the drives around and I’m back to square one. Any ideas?

 

[Capt. 2110]

Final update: I was using a “12V 5A” power supply, but apparently that’s not enough for the Zenith. It wants its original power supply (12V 2.5A, but also not chintzy garbage). So after fixing that, everything works again!